As chief hoarder and most disorganized (my self-appointed voluntary position <g>) I can not imagine why anyone would want to do what you are setting out to do????
My mother always said: If you create an appetite for something, the appetite will have to be fed ...
and, buying more fabric than one could use in five lifetimes, just isn't practical, but I only started buying a yard here, a yard there ... oh, I could put that into a theme quilt I might make fifteen years from now, since I really don't have time to complete the 25 quilts that need to be quilted right now ....
are you hearing me???? You are about to make a BIG mistake!
Now ... having said all that, I did note that you said you liked to just make a block once in awhile, rather than a whole quilt ...
well, by golly! Go buy some fat quarters and make some blocks! A sampler, I suppose is what you are thinking of ... and, you are probably wanting to try different techniques, and don't need a whole quilt to accomplish the feat.
I get that ...
I helped my sister in law build her stash by talking to her about the TONS of good fabric I have seen in thrift stores ... clothes that are barely worn .. men's shirts ... skirts ...
garage sales ... you can't believe the sheet sets and fine fabric you can pick up less expensively that having to go buy brandy new fabric all of the time ...
and, just start sharing your new interest among friends and family! You can't possibly imagine the people around you who have lots of fabric that they were waiting to share with someone because mom's fabric isn't what they wanted to own, anyway ... or Aunt Tilly just died, and we are cleaning out her house ... we just want it gone! Do you want it?
Happens all the time <g>.
Proceed cautiously <wave>